Flexible roof furling system for amphitheaters or the like



Oct. 26, 1954 fi- 2,692,566

FLEXIBLE ROOF FURLING SYSTEM FOR AMPHITHEATERS OR THE LIKE Filed Feb. 6 1950 5 Sheets-Sheet l INVENTOR JAMESA. MITCHELL Cd. 26, 1954 J. H L 2,692,566

FLEXIBLE ROOF FURLING SYSTEM FOR AMFHITHEATERS OR THE LIKE Filed Feb. 6, 1950 5 Sheets-Sheet 2 INVENTOR JAMES A. MITCHELL Oct. 26, 1954 J. A. MITCHELL 2,692,566

FLEXIBLE ROOF FURLING SYSTEM FOR AMPHITHEATERS OR THE LIKE 5 Shets-Sheet 3 Filed Feb. 6 1950 R O T N E V m JAMES A.M|TCHELL MG! 5444 W Oct. 26, 1954 J. A. MITCHELL 2,692,566

FLEXIBLE ROOF FURLING SYSTEM FOR AMPHITHEATERS OR THE LIKE Filed Feb. 6, 1950 5 Sheets-Sheet 4- 4 INVENTOR JAMES A. MITCHELL Oct. 26, 1954 J. A. MITCHELL 2,692,566

FLEXIBLE ROOF FURLING SYSTEM FOR AMPHITHEATERS OR THE LIKE Filed Feb. 6 1950 5 Sheets-Sheet 5 INVENTOR JAMES A.MITCHELL atented Oct. 26, 1954 UITED STAT PTENT OFFICE FLEXIBLE ROOF FURLKNG SYSTEM FOR AMPHITHEATERS OR THE LIKE 13 Claims.

This invention relates to mechanisms whereby an open-air theater, stadium, arena, field for sports, or other open-air facilities and the like may be covered with a flexible roof in inclement weather or on days the occupants thereof or the facilities therein are to be shielded from the sun's rays. More particularly, this invention relates to flexible roof furling and unfurling systems which operate in the manner of a fan or series of fans supported at the center in such fashion as to preferably avoid interference with the view of the spectators within the roofed area and/or provide clearance for the facilities therein.

A problem has long existed relating to the protection of open-air congregations witnessing theatrical entertainments, sports and other events and functions, against the effects of storms or excessive sunlight. This problem has been particularly acute in connection with open-air summer theaters and concert parks, for example, in which the attendance season may be relatively short. Hence, the inability of a performance or function to take place as scheduled because of the occurrence of rain or other inclemency, or the discontinuance of such performance or festivity because of the sudden arising of a storm, adversely affects the finances of the enterprise and at the very least inconveniences those concerned and their plans.

On the other hand, the charm of many performances and functions which can be produced in the open air in good Weather would be lost if such performances and functions were to take place indoors. Yet, the difficulty of suitably covering a large assembly of people in an openair theater or stadium in a relatively short time and of uncovering the theater or stadium when such protection is no longer required has remained.

In the present invention, the foregoing difiiculties are overcome, making it possible to schedule events in the open air with assurance that those in attendance can quickly be protected should the need arise. Other objects and advantages will appear from the following description and drawings, which are illustrative only, in which Figure 1 is a schematic plan view of an openair amphitheater or the like partly covered and partly uncovered in the manner provided by this invention;

Figure 2 is a schematic view in cross section taken generally along the line II-Ii of Figure 1;

Figure 2A is a detail view of one means which may be used to fasten flexible or fabric covering material to the radial members;

Figure 3 is an enlarged View of the pivotal connections at the inner ends of the radial members shown in Figure 1;

Figure 4 is a view taken generally from one side of one of the radial members shown in Figure 1 showing the connection at the outer end thereof;

Figure 5 is a schematic plan View of a drive suitable for the radial members in the mechanism for one side of the amphitheater shown in Figure 1;

Figure 6 is a view in cross section taken along line V-V of Figure 4;

Figure 7 is a detail plan view of the portion of Figure 5 showing the link to the radial members;

Figure 8 is a schematic view of a modification of connections suitable for the inner ends (shown in covering or unfurled position) of the radial members shown in Figure 1 when using a rigid leading bounding radial member;

Figure 9 is a View in cross section (with the inner ends of the radial members shown in closed or uncovering position) taken along line IX-IX of Figure 8;

Figure 10 is a view of a modification of connections suitable for the outer ends of the radial members shown in Figure 1 when using a rigid bounding radial member;

Figure 10A is a view in cross section taken along line XA-XA of Figure 10;

Figure 11 is a view in cross section taken along line XI--XI of Figure 16;

Figure 12 is a schematic plan View, greatly reduced, of a gear ring drive suitable for use with the assembly shown in Figures 10 and 11;

Figure 13 is a view of a further modification of connections suitable for the inner ends of the radial members shown in Figures 8 and 9;

Figure 13A is an enlarged detail view in cross section through one of the clamps shown in Figure 13;

Figure 14 is a View in cross section taken along line XIV-XIV of Figure 13;

Figure 15 is a view in cross section taken along line XV-XV of Figure 13;

Figure 16 is a plan view partly in cross section of a further modification of connections suit able for the outer end of a rigid leadingbounding radial member;

Figure 1'7 is a view in cross section taken along line XVII-XVII of Figure 16;

Figure 18 is a view in perspective of a further modification of connections suitable for the outer ends of radial members in the form of cables;

Figure 19 is a view in front elevation of a still further modification of connections particularly suitable for the outer ends of radial members in the form of cables;

Figure 20 is a view of such still further modification taken along line XX-XX of Figure 19;

Figure 21 is a view in cross section of a seal suitable for use between rigid leading bounding radial members, such as those shown in Figure 9; and

Figure 22 is a schematic view of a modified supporting beam or arch construction suitable for use in connection with this invention.

Referring to Figures 1 and 2, an open-air amphitheater i is schematically depicted therein built on a slope H. Arcuate tiers 12 of masonry are supported on a foundation l3. A center aisle l4 and side aisles I5 may be provided as passageways between the tiers and through the amphitheater. A masonry wall l6 encloses the sides of amphitheater l0 and is provided with a generally horizontal top surface [1. Buttresses l8 extend around wall [6 in conveniently supporting relationship thereto. Immediately inside wall IS a masonry trench I9 may be provided and divided into compartments by radially extending terracing partitions 20. When filled with earth the compartments of trench l9 provide the soil for decorative floral plantings around substantially the entire inner periphery of amphitheater ln. Drainage and sewerage connections for trench l9 and for the amphitheater as a whole may be provided by means of a subterranean trench 2|. A stage 22 may be built at the foot of tiers I2 and provided with masonry wings 23 behind which stairways 24 afford ac cess to rooms 25 beneath stage 22. A further series of rooms 26 may be provided at the top of tiers l2.

In the practice of this invention a cantilever supporting beam 2! may be provided having its outer end 28 anchored in a massive footing 29 adjacent to wall I6 at a point directly in back of tiers 12. A leg 30 bears on a massive footing 3| near the top of aisle [4 to complete the support for beam 21 which may be constructed of the various steel members necessary to build up the final rigid cantilever beam. Since beam 21 arches over amphitheater [0, it will not obstruct the view of the spectators occupying the tiers I2.

A mast 32 is provided at the inner end of beam 21 and extends upwardly. Mast 32 is approximately coaxial with the center of wall surface ll. Generally top wall surface I: will be circular but may be arcuate or regularly curved in such manner so as to have a central focus through which a mast such as mast 32 may pass and thus be substantially equidistant from all parts of the are or curve in question.

A plurality of radial members 33 extend between mast 32 and surface I1 and are respectively connected thereto at their inner and outer ends. These radial members 33 are preferably divided for the respective sides of amphitheater l0 and when extended in fanwise fashion as shown in Figure 1 will cover the amphitheater. When fanned closed to open the roof the radial members 33 form a relatively small sector as partly illustrated by the half of the members on the left-hand side of Figure 1. Since an equal number of radial members is provided on each side of beam 21, when both sides are fully extended a complete 360 coverage of the amphitheater is effected. When so covered the leading or bordering bounding radial members 34 are together and leave no gap in the supporting structure for the unfurled roof. The other bounding radial members 35 are usually fixedly attached to beam 21 or to wall it by anchor bolts or otherwise.

Reinforcing members 36 may be employed extending radially from a point adj mast 32 to a point intermediate the respective radial member 33 so supportably reinforced. Suitable conventional clamps may be used for the joint between the respective members 36 and 33. The inner ends of the radial members 33 with the reinforcing members 33 are respectively pivotally connected to mast 32 as illustrated in more detail in Figure 3. The outer ends of radial members 33 are movably connected to wall surface I! as more fully shown in Figures 4 to '7. When reinforcing members 36 are used, the structure may be so designed that radial members 33 carry the weight of the fabric cover 31, the live load and the internal wind pressure, while reinforcing members 35 may assist in carrying dead and live load and the force of the external wind pressure.

A flexible covering 31 is provided and so connected to radial members 33 with its edges fastened to members 34 that when the respective members 33 on each side of amphitheater H) are fanned open, covering 3'? is unfurled so as to resemble in the embodiment shown in Figures 1 and 2 the covering of a tepee since members 33 in such position are generally conical or pyramidal when viewed from the side. The pitch or the radial members 33 between their respective inner and outer ends is such as to give efficient drainage as in the case of rain. The outer edge 33 of cover 3'! may be located directly above trench i9 so that rain may fall into that trench and any excess water removed through drain 2|.

The flexible cover 31 may be any suitable material whether of fabric or fibrous character as in the case of canvas, Orlon, nylon, rayon, fibre glass cloth and others, or of non-fibrous character as in the case of certain synthetic and plastic materials. The fibrous materials may be coated either with vinyl resins, neoprene or other suitable substances in accordance with the skill of those in that art.

Referring to Figure 3, mast 32 has mounted thereon a lower annular track 39 and an upper annular tracl: 40. Track 39 comprises a lower disc 4| and an upper conical disc-like part 42 in spaced relation defining a slot 43 through which the radial members 33 may pass. The outer edges of parts 4! and 42 are flanged toward slot 43 to provide a track on each side of the slot. Gusset plates 44 firmly fix parts 4| and 42 to mast 32. The general construction and mounting of track is the same as in the case of track 39 except that reinforcing members 36 pass through the slot of track 43. The radial members 33 and reinforcing members 36 are cables in the embodiment being described although rigid members may be substituted in some cases. Each cable 33 extends upwardly and passes through an opening drilled through the center of a trolley shaft 45. Shaft 45 with trolley wheels 46 respectively riding in the flanges of track parts 4| and 42 provides a pivotal and rotatable connection between each such cable 33 and mast 32.

The reinforcing cables 36 pass through a trolley plate 4! and are affixed thereto as by a nut. Ball bearings 48 are rotatably positioned in corresponding recesses on the side of plate 41 toward the flanges of the parts of track 493, thus making reinforcing cables 36 also pivotal and rotatable relative to mast 32. Each cable 36 receives its motive force through its connection with its corresponding radial cable 33. Either trolley wheel or ball bearing end holders may be used for both radial cables 33 and 36. Although mast 32 is shown as fixed, provision may be made whereby a rotatable mast 32 can be employed with consequent diminution of the need of the respective trolleys for cables 33 and 35 to be rotatable relative to mast 32.

A conical rain cap is mounted on mast 32 in sealed relation thereto and acts as a flashing in overlying the inner edge 33a of the cover 31. Hence, cap 49 sheds any rain or snow which falls thereon onto cover 31 whence it is drained away. Cover 31 may be fastened in a number of ways to the radial members 33 (including the bounding radial members 34 and 35) as illustrated in Figure 2A. Therein, flap pieces 50 with grommets therein are affixed to the underside of cover 37 along appropriate portions of each of the radial members 33 to which the cover is to be fastened. A lace Si is woven through the grommets on the opposite side of the member 33 from cover 3'? thereby providing a suitable fastening. And in some cases it may be desired to have the cover suspended by such means from the radial memhere.

The outer ends of radial cables 33 may each be branched as shown by the branches at and 1) whenever the span from mast 32 to surface ll warrants. Whether or not so branched, the outer ends of cables 33 may be connected to surface I! in movable relation thereto as illustrated in Figures 4 to '7. At circumferentially spaced intervals around the peripheral surface H are a series of anchors 52 and 53 embedded in the masonry of wall iii. In some cases the wall It may be dispensed with by having the anchors aflixed to sufficiently strong columns spaced at suitable intervals around the periphery of the amphitheater. A continuous lower track plate 54 is riveted or otherwise fastened to the respective anchors 52. A continuous upper track plate 55 is connected by rivets or other suitable fastening to the respective anchors 53 and in spaced relation to plate 5 so as to define a track slot 56 therebetween. Tracks 51 suitably grooved are fastened on the side of track plates 54 and 55 away from mast 32. The lower or outer ends of radial cables 33 are provided with a thimble ring end 58 through which an L-headed bolt 59 is passed. The stem of bolt 59 passes through slot 56 and a drilled opening through a trolley shaft 6!). Since the lowermost end of bolt 59 is threaded, a nut 59a secures bolt 59 and cable 33 to the shaft '50. The adjustment of nut 59a may be used to change the tension and hence the catenary curve of the respective cable 33. A pair of trolley wheels 6! are rotatably secured to trolley shaft 6i] and their peripheries engage the grooves in the two tracks 5?. Hence, as the trolleys 6ll6i are moved in either direction along track 5l-5l, the cable 33 and reinforcing member 36 connected thereto is correspondingly moved about mast 32 as a center.

A lug 62 is welded to the center of shaft 60 on each side thereof and extends generally parallel to the plates 5455. A further lug 53 is welded to shaft 60 on the leading bounding radial cables 34 and extends in a generally radial direction. Pre- 6, determined lengths of chains 54 are respectively connected to the lugs 62 on adjoining shafts '60 for each half of the mechanism covering amphitheater IIJ. Another length of chain 65 extends between lug 63 and link 65 to move cable 34 away from beam 2? about mast 32 when fanning the two halves of the roof mechanism open and toward beam 21 when the two halves of the roof mechanism are being closed. In so doing, during the opening operation, the chain lengths 6 3 are respectively extended beginning with that length connected to radial member 34. Conversely, in closing the roof mechanism, the lengths 65 beginning with the length connected to radial member 34 are collapsed in succession. The lugs 62 are of sufficient length exceeding the radius of the trolley wheels 5! so that wheels 6| do not frictionally rub as the roof mechanism is closed.

The driving mechanism for the connection shown in Figure 4 for one-half of the roof mechanism is schematically illustrated in Figures 5 to 7. In this driving mechanism an endless sprocket chain 6'! is in engagement with end sprockets '68 and guiding sprockets B9. Keeper sprockets l'il may be employed to insure proper tensioning of chain 51 and avoid mechanical breakdown. One of the end sprockets S8 is directly or indirectly driven by a prime mover and reduction gear assembly (not shown) either in synchronism with the driving mechanism for the other half of the roof mechanism or separately as desired. Lugs H are provided on two of the links of chain El and are so drilled that a pin '52 connects the lugs H to link 86, leaving link 68 free for limited movement about a horizontal axis. A curved hood l3 furnishes the necessary support for the upper ends of the various sprocket shafts and shields such sprockets from the en-- trance of foreign material. The link 6t reciprotates in the outer arcuate path between the end sprockets 58 which reverse through the medium of limit switches (not shown) in the prime mover assembly for the driving mechanism.

In operation, therefore, when the two halves of the roof mechanism are fanned open so that the leading radial members 3 3 are adjoining, the entire amphitheater Ill is covered by cover 3?. When the roof mechanism is opened, stretching the chord distances between adjoining radial members 33 to a maximum as determined by the length of each one of the uniform lengths of chain 65, cover 31 is sufficiently taut to effectively shed any rain that may fall upon it. When the amphitheater is used in the daytime hours, it can also be covered by the roof system of this invention whenever it is to be shielded from the too bright or too hot rays of the sun. At the same time, should a storm suddenly arise, the driving mechanism chains 55 and 61 in a single traverse can extend cover 31 in place over the amphitheater and as readily remove it when the storm has passed. When the roof of amphitheater I 0 is open, that is to say when the mechanism is closed, the cover 3'! is furled and hangs down in regular relatively quick-drying, single folds between the respective radial members 33 on each side of beam 21.

In Figures 8 and 9 a modification is shown whereby the inner ends of the radial members of the roof mechanism may be, pivotally connected about a mast 32 corresponding generally in purpose and construction to mast 32. In addition, a rigid leading bounding radial member 3 3' in the form of a rigid lightweight beam is used in the modification shown in Figures 8 and 9 with remainder of the radial members 33' for covering each half of the amphitheater provided in the form of cables. Each cable 33' is suitably connected to a vertically trunnioned pivot 80, the vertical journals 8| of each of which are rotatably supported in bushings in the top and bottom overhanging portions of an inclined recess 82 in mast 32'. A correspondingly inclined recess 82 is on the other side of mast 32 at the same level to take care of the radial cables 33 for the other half of the roof mechanism. Each recess 82 slopes downwardly from the front of the amphitheater or the like to the rear thereof assuming that when the roof mechanism halves are closed that they extend rearwardly substantially as illustrated on the left-hand side of Figure 1 relating to another modification of this invention. The cables 33' are shown in Figure 8 in covering or opened position, whereas in Figure 9 they are shown with the roof mechanism in closed position. The bushings for each of the vertically trunnioned pivots fit into radial slots in mast 32 and are held in place by the clamps 83.

Reinforcing cables 36 corresponding to reinforcing cables 30 in the modification shown in Figure 3, are provided with similarly trunnioned pivots, bushings and bushing positioning clamps. The trunnioned pivot for a reinforcing cable 36 is directly above and on the same center line as the pivot 80 for the radial member 33 to which the respective reinforcing member 36' is conneoted.

Rigid leading radial member 34 which may be made of a light, high strength metal alloy is provided at the upper end thereof with a tongue 84 having an integral sleeve 85 at the uppermost end thereof through which a hinge pin 86 is passed. A socket comprising a lower part 81 and an upper part 88 is drilled for the reception of hinge pin 86 and in interleaved relation with sleeve 85 so that pin 86 acts as a center for the swinging of rigid radial member 34'. One such socket is provided on each side of mast 32' below and adjacent recess 82.

A peripheral wall I6 corresponding in construction and purpose to wall I6 is provided with a peripheral top surface IT as shown in Figures 10 to 12. A number of gusset anchors 89 support a continuous track plate 90 in cantilever fashion around the inner edge of the curved Wall I6 and extending above surface H. A continuous double railed track 9| is fastened to plate 90 on the side away from mast 32'. Grooved wheels 92 ride on the raised rails of track 9i and are connected to each other by a shaft 93. Shaft 93 extends upwardly and outwardly and is rigidly held in an anchor plate 94. Each anchor plate 94 has a downwardly extending lug 95 thereon through the center of which an L-headed bolt 96 slidably passes. Bolt 96 is threaded at its lower end 9'! and by means of a spring retainer 98 and nut 99 retains a spring I between lug 95 and retainer 98. The upper end of bolt 96 is connected to the lower ends of the radial cables 33 in the same way that bolts 59 are connected to members 33.

Anchor plate 94a to which the outer end of rigid leading radial member 34 is affixed is provided with angle shaped guides IOI on the underside thereof. These guides IOI are welded to plate 94a and slidably guide axial movement of the outer end of member 34 relative to plate 94a to take due account of any changes in length due to thermal conditions or any shifts in the axial relation of member 34' to plate 94a due to any slight unevenness in track 9|. Springs I02 are respectively fastened on each side of member 34' around bolts 96a which pass through drilled bosses a. Bosses 9511. are integral with plate 94a. Spring retainers 98a and nuts 99a complete the assembly and function as in the case of parts 98 and 99.

The driving mechanism for the modification shown in Figures 9 to 13 comprises an outer semicircular ring gear I03 and an inner semicircular ring gear I04 for the respective halves of the roof mechanism. Ring gear I03 is provided with teeth I05 in meshing engagement with a driving pinion I06. Pinion I06 is appropriately driven through a gear reduction assembly by a prime mover such as an electric motor (not shown). Ring gear I04 is provided with gear teeth I01 around the inner periphery thereof which gear teeth I01 are in meshing engagement with another driving pinion I08. Driving pinion I08 is driven through a gear reducing assembly by a prime mover such as an electric motor (not shown). The driving mechanism for the two ring gears I03 and I04 may be interconnected for synchronized action or separately operated in respect of each ring gear controlling the movement of its one-half of the roof mechanism as shown in Figure 12.

Each ring gear is provided with a roller bearing plate I09 mounted for movement in a channel track III). The channel track IEO for ring gear I03 will be concentric with relation to the channel track IIO for gear I03 and inwardly thereof. The two channel tracks H0 are complete circles inasmuch as each ring gear is rotatable through approximately in moving the respective halves of the roof mechanism from full-open to full-closed or from full-closed to full-open position. Each ring gear has welded thereto a plurality of ratchet supporting plates IiI equal in number to the number of radial members 33' concerned and in spaced relation to each other equal to the maximum desired chord distance between the respective radial members 33'. Each plate I I I has an upper and lower part parallel to each other and slotted at I I2 in registry. Spring pockets II3 are also affixed by welding or otherwise to one or both such parts of the plates lII outwardly from the slots II2. A hook-shaped ratchet lever II4 having a hook portion H5 is fixed on a transverse rectangular shaft IIB adapted to slide in the slots II2. A cam II! is also affixed to shaft II6. Cam IIl has a segmental portion II8 extending upwardly between the innermost ends of the upper plate I II in the path of the outermost ends of the anchor plates 94 and 94a. A spring I20 of predetermined strength is seated in each of the pockets H3 and bears against outer peripheral portions of cam I H. A latch I2I may be pivoted in a recess adjacent the opening of hook portion I I5 and maintained in resilient latching position by two springs I22 also recessed within the body of ratchet lever H4. The springs I22 do not have sufficient strength to prevent the movement of latch I2I when hook portion II5 disengages from or engages the respective shafts 93 between the grooved wheels 92 attached to anchor plates 94 and 94a. The purpose of each latch I2I is to prevent any casual dislodgment of its respective hook portion II5 due to incidental movements which may take place in the driving mechanism as distinguished from positive operation of the levers H4 during the opening or closing of the roof mechanism by the ring gears I33 and I 04. The ratchet plate and lever assemblies of both ring gears are the same except that they are faced in opposite directions as shown in Figure 12 in Which a pitch line I I4 indicates the successive presence in spaced relation of the respective ratchet plate and lever assemblies.

When ring gear I43 is rotated in a clockwise direction, it will close its half of the roof mechanism and thereby uncover or open the roof of the protected structure. In so doing, each of the segmental bosses H8 simultaneously strikes its respective anchor plate 34 or 94a. The radial member 33 adjoining innermost radial member 35' will thereby have its anchor plate 34 brought into abutting relation with a stop fixed to the structure or a fixed anchor plate connected to the outer end of radial member 35'. Continued rotation of ring gear I03 will force the segmental boss II 8 abutting anchor plate 94 on that adjoining radial member 33', outwardly. This outward movement is permitted by the sliding of shaft I It in the slots I I 2 compressing the springs I20. Such springs are selected of such predetermined strength that the segmental boss IIS can perform the closing action without moving outwardly but it must move outwardly when its anchor plate 94 is held positively against further movement. As the successive anchor plates 34 similarly abut and stop, the corresponding ratchet levers H4 are disengaged by the camming of the respective bosses H3 outwardly and unhooking the respective ratchet levers H4 from the shafts 33, until finally anchor plate 94a is brought to a halt with the fan members 33' closed.

A beam I23, corresponding generally in function and purpose to beam 2'! in the earlier modification, may act as the stop during the closing of the radial members 33' and radial member 34'. As in the earlier modification the bounding radial member 35' adjoining beam IE3 is connected thereto or to wall I6 to anchor that edge of each half of the roof mechanism. At the same time, the radial cables 33' are not only close together when so closed but are successively elevated when viewed proceeding from the cable 35 next to beam I23 toward leading radial member 34'. This successive elevation is caused by the upwardly and forwardly inclining of the recesses 82 which tends to somewhat reduce the area of the vertical projection of the radial members on a horizontal plane, thus affording clearance and reducing the space occupied when closed.

As ring gear I33 is rotated in a counterclockwise direction, the first ratchet lever I I4 reengages shaft 33 connected to anchor plate 34a as the segmental boss IE8 moves inwardly as plate IE3 passes beyond anchor plate 34a. Continued clockwise rotation of ring gear Hi3 similarly individually reengages the succeeding levers H4 with the respectively succeeding shafts 93 and fully extends that half of the roof system. A corresponding retraction or extension of the other half of the roof system is performed by the respective counterclockwise or clockwise rotation of ring gear I04. A cover is connected to the radial members 33 (including members 34 and 35') as described in the earlier embodiment of this invention.

In place of the spaced ratchet plate and lever assemblies III and H4, the ring gears I93 and I34 may be provided with a link connected to anchor plate 34a by a chain corresponding in purpose and function to chain 65 of the earlier described embodiment of this invention. In such 10 a case, the respective radial members 33' on each side of the protected structure would be provided with spacing chains corresponding to chain links 64 and would operate in the same manner insofar as the opening, closing and spacing of the respective radial members are concerned.

In a still further modification of this invention, a beam I30, corresponding to beam 21 in an earlier described embodiment, has a central mast I3I. On mast I3I there is a lower split cable clamp I32 having a movable part I32a and an upper split cable clamp I33 having a movable part I33a. The other halves of the clamps I32 and I33 are fixed and integral with mast I3I. Parts I32a and I33a are held in their respective clamping positions by horizontal bolts I34. Each of the clamp halves is substantially semicircular in horizontal cross section and placed in tangential position relative to the other half of the clamp. Since the fixed halves of each clamp, as shown in Figure 13A, are provided with grooves or serrations I3Ia, each cable held by each clamp is vertically spaced relative the adjoining cables held by such clamp. Radial cables 33" are held in clamp I32 and correspond in general function and construction to cables 33 and 33. Reinforcing cables 36" are held in clamp I33 and correspond in general purpose and construction to reinforcing members 36 and 36.

A rigid beam I35 comprises the leading bounding radial member on one side of beam I30 and is pivotally connected to a collar I36 which is rotatable relative to a depending portion I3! of mast I3I. A bearing I38 fixed around portion I31 supports the thrust of collar I36. A spacing bearing I39 supports another collar I43, similar to collar I36. Collar I40 has pivotally connected thereto a rigid beam I4I which constitutes the leading bounding radial member on the other side of beam I30. An upper roller bearing I42 is fixedly mounted on mast portion I31 above collar I43 to complete the bearing assembly for the inner ends of the two radial members I35 and MI. Each of the radial members I35 and MI corresponds in purpose to the radial members 34 and 34 described herein in connection with other embodiments of this invention. In this further modification the respective radial cables are provided with suitable clearance.

The outer end of rigid member I35 is provided with a recess I43 into which project opposed coaxial supporting bearings I44. These bearings engage cooperating sockets in a motor assembly I45. A peripheral wall I6", similar in general construction and purpose to wall It and I6 de cribed in earlier modifications, is provided with an irregular top surface I 'I" having formed therein a track face outwardly of the center of the amphitheater on which a continuous track I46 is mounted. Inwardly of track I46 there is another continuous track I 41 on surface II" which supports the outer end of rigid member I35 and its motor assembly I45. The other half of the same track is similarly used by rigid member I4I with its motor assembly. Both rigid members I35 and MI and both motor assemblies I45 are substantially identical but opposite.

In motor assembly I45 grooved guide wheels I48 engage track I41. A driving wheel I49 enclosed in a hood I50 is turned by a reversible electric motor I5I suitably mounted in the structure of assembly I45. The electric current for motor I5I may be provided by means of a third rail for each one-half of track I41 covered by the respective motor assemblies or by electric current leads fastened to the rigid radial members I35 and MI and in turn to beam I30 where a suitable source of electric power may be provided by a distribution transformer or other such means (not illustrated).

The outer end of each of the radial cables 33 is provided with a thimble ring I52 which encircles a rod I53 held by the inner ends of a trolley carriage I54. Trolley carriage I54 ha a depending flange I55 overlying the wall face on which track I46 is mounted. Grooved trolley wheels I56 are rotatably aflixed to carriage I54 and flange I55 50 as to engage track I46 and hold the cables 33" at the proper tension while allowing fanwise movement thereof in covering or uncovering the amphitheater or the like in which they are employed. Spacing lengths of chain or cables corresponding to the chains 64 in an earlier described embodiment are provided between adjoining radial members 33". In this way, rotating motor II for member I35 in one direction and the corresponding motor in the motor assembly for rigid member MI in the opposite direction will move the respective rigid members I35 and MI away from beam I30 until they meet on the far side of the amphitheater to form a complete roof structure thereover.

A suitable fabric or flexible cover corresponding to cover 3'! is connected to the rigid members I35 and MI and such of the intermediate supporting radial members 33" as may be desired. As the rigid members i35 and MI move in fanwise fashion into covering position, the chain lengths between the respective radial members in each half of the roof mechanism will pull the carriages I54 along generally in successive fashion until each ha achieved its maximum distance from the adjoining radial member or members indicating that the roof mechanism is fully opened. When the current is reversed in the respective motor assemblies, the rigid members I35 and MI will abut the adjoining carriages and in turn the chord distance between adjoining radial members will be reduced gen erally succesively proceeding with those next to the rigid members I35 and MI respectively. This closing action will continue until the rigid members I35 and MI are as close to beam I30 and on each side thereof respectively as the physical widths of the carriages I54 will allow.

In Figures 19 and 20 another form of a trolley carriage 154 is shown in which adjoining carriages I55 have connected thereto grooved wheels I55 on successively alternating levels. Track I46 and I46" are respectively provided on these levels. Hence, when each half of the roof mechanism is closed using the carriage form shown in Figure 19, some overlapping of the wheels of adjoining carriages I54 may take place, reducing the area of the vertical projection on a horizontal plane required by each half of the roof system mechanism when so closed.

In Figure 21 a cross section is shown of a suitable sealing closure for the joint between the adjoining faces of rigid leading radial members,

such as members 34' or members I35 and MI. In Figure 21, the leading edge of one of the rigid members may be provided with a flange I60 and a sealing gasket I6I so that as the other leading radial member comes into covering relation thereto, the shield I60 and gasket I6I prevent any water from falling between the rigid mem- 12 bers in question, making it run down where it can fall into a trench such as trench I9. When the leading radial members are in the form of cables similar sealing provision may readily be made on the cover portion fastened to such cables.

A number of other modifications may be made which are within the spirit of this invention and the scope of the appended claims. For example, as shown in Figure 22, a full arching beam I62 may be employed for an amphitheater I63. A depending mast I64 hanging from beam I62 can provide the necessary support for the inner ends of the radial members of the two halves of the roof mechanism I65. Suitable connections for the outer ends of the radial members mounted on the peripheral wall I66 and a cover will complete the roof structure made in accordance with this invention.

Very large covers may if desired be made in detachable sections capable of being suitably joined together. In some cases, moreover, a plurality of arches intersecting with each other at the center may be used to support a roof system made in accordance with this invention. For use over stadia and the like, each curved end may be covered by a roof system of this invention with appropriate cover protection if desired to arch over the straight portion of the stadia between the curved ends to complete the roof protection.

Further, although the roof mechanism illustrated in the foregoing embodiments is generally conical or pyramidical when in open, that is covering, position, it may also be made in the form of an inverted cone by increasing the height of the peripheral wall in which case drainage could be conducted into a duct at the center of the structure and taken out along the supporting arching beam without obstructing the view within the open-air amphitheater or the like. In addition in cases where obstruction of the view is not a material factor, a central mast extending upwardly from the ground or structure directly below may be employed. Still further, instead of a peripheral wall, a ring girder may be used supported on suitably spaced columns. The top wall surface described herein or the surface provided by the aforesaid ring girder should be substantially planar but need not be horizontal in cases where some inclination thereof may suit the terrain or other purpose better.

I claim:

1. In a flexible roof furling system for amphitheaters or the like, in combination, an arcuate track adjacent the periphery of the portion of said amphitheater to be covered, a beam extending to the axis generally about which the arc of said track is described, a plurality of radial members swingably connected to said beam and extending between said beam and said track, means movable along said track connected to the outer ends of said radial members, a flexible cover for said radial members, and means for moving said first-mentioned means along said track to cover and uncover said portion of said amphitheater or the like.

2. In a flexible roof furling system for amphitheaters or the like, in combination, an arcuate track adjacent the periphery of the portion of said amphitheater to be covered, a beam extending to the axis generally about which the arc of said track is described, a plurality of radial members swingably connected to said beam and extending between said beam and said track,

said radial members further having outer branched ends, means movable along said track connected to said branched ends, a flexible cover for said radial members, and means for moving said first-mentioned means along said track to cover and uncover said portion of said amphitheater or the like.

3. In a flexible roof iurling system for amphitheaters or the like, in combination, an arcuate track adjacent the periphery of said amphitheater, a beam arching over the amphitheater, said beam extending at least to the position of the axis about which the arc in said track is described, radial members extending between said beam adjacent said axis and said track and respectively connected to each thereof, means in movable engagement relative to said track and connected to said radial members to fan out said radial members to extend over said amphitheater between said axis and said track, and a flexible cover supported by said radial members substantially between said beam and track, whereby when said radial members are fanned open said cover is spread and when said radial members are fanned closed said cover is furled.

l. In a fabric roof furling mechanism for amphitheaters or the like, in combination, an arcuate traclr substantially defining at least a portion of the periphery of said amphitheater, a beam arching over the amphitheater from a point adjacent the periphery thereof at least to a position through which the center axis of said arcuate track passes, radial members pivotally connected to said beam adjacent said center axis and extending to said arcuate track, means in movable engagement with said arcuate track, said means being connected to said radial members, means for moving said last-mentioned means along said arcuate track to increase or decrease the chord distance between adjacent radial members, and a cover connected to said radial members and adapted to be extended when said chord distances are at a maximum and to hang down in folds between said radial members when said chord distances are at a minimum, whereby the sector of said amphitheater defined by said center axis and arcuate track may be opened to the sky during clear weather and covered during inclement weather.

5. In a flexible roof furling system for amphitheaters or the like, in combination, a generally circular track adjacent the periphery of said amphitheater, a beam arching overthe amphitheater from a point adjacent the periphery thereof and extending to the position of the axis of the center of said track, a central mast coaxial with said axis supported by said beam, radial members pivotally connected to said mast and extending to said track, said radial members having a pitch between the respective ends of each thereof, means in movable engagement with said track, said means being connected to said radial members, means for moving said last-mentioned means along said track to change the chord distance between adjacent radial members, and a flexible cover connected to said radial members and adapted to be extended when said chord distances are at a maximum and to hang down in folds between said radial members when said chord distances are at a minimum, whereby the portion of said amphitheater defined by said cover when extended may be opened to the sky during clear weather and covered during inclement weather substantially without obstructing the view within the amphitheater.

6. In a flexible roof furling system for an amphitheater or the like, in combination, an arcuate track adjacent the periphery of the portion of said amphitheater to be covered, a beam arching over said portion, said beam extending at least to the position of the axis about which the arc in said track is described, an inner track connected to said beam substantially about said axis, a plurality of radial members extending between said respective tracks, said radial members having their ends connected to trolleys movably engaging said respective tracks, a flexible cover for said radial members, and means for moving said trolleys at the outer ends of said radial members along said curved track to cover and uncover said portion of said amphitheater.

'7. In a flexible roof furling system for amphitheaters or the like, in combination, an arcuate track adjacent the periphery of the portion of said amphitheater to be covered, a beam arching over said portion, said beam extending at least to the position of the axis about which the arc in said track is described, a plurality of radial cables extending between said axis and said track, said radial cables being pivotally connected to said beam substantially about said axis in sideby-side inclined relation, said radial cables further being resiliently and pivotally connected at the outer ends thereof to said track, means for moving the outer ends of said radial cables along said track, and a flexible cover connected to said cables substantially between said axis and track, whereby when said radial cables are drawn together said cover is furled to uncover said portion of said amphitheater and the inner ends of said radial cables are afforded clearance by said inclined pivotal connection.

8. In a flexible roof furling system for amp-hitheaters or the like, in combination, an arcuate track adjacent the periphery of the portion of said amphitheater to be covered, a beam arching over said portion so as not to obstruct the view within the same, said beam extending at least to the position of the axis about which the arc in said track is described, a plurality of radia1 cables extending between said axis and said track, said radial cables being pivotally connected to said beam substantially about said axis, a plurality of carriages in hooked rolling engagement with said track, said carriages being connected to the outer end of said radial cables and adapted to hold said radial cables under a predetermined tension, a further plurality of reinforcing cables, said reinforcing cables being pivotally connected at their inner ends to said beam substantially about said axis, said reinforcing cables being respectively connected at their outer ends to said radial cables intermediate the ends of said radial cables, a flexible cover for said radial cables, and means for moving said carriages along said track to open and close said radial cables to cover and uncover said portion of said amphitheater.

9. In a flexible roof furling system for amphitheaters or the like, in combination, an arcuate track adjacent the periphery of the portion of said amphitheater to be covered, a beam arching over said portion, said beam extending at least to the position of the axis about Which the arc in said track is described, radially disposed cables pivotally connected at the inner ends thereof to said beam adjacent said axis, said cables being respectively connected to said track in movable relation thereto, means for fanning said radial cables open and closed, a flexible cover supported by said radial cables, said cover being secured at one end thereof to a radial member and extending across the other radial members and. having its other end secured to a radial member movable into proximity with said first mentioned radial member when said cover is furled, and means for spacing the distance between said cables when in open position.

10. In a flexible roof furling system for amphitheaters or the like, in combination, an arcuate track adjacent the periphery of the portion of said amphitheater to be covered, a mast rising above said amphitheater and substantially coinciding with the position of the axis about which the arc in said track is described, radial members extending between said mast and said track and respectively connected to each thereof, said radial members being circumferentially movable relative to one another, a flexible cover for said radial members, said cover being secured at one end thereof to a radial member and extending across the other radial members and having its other end secured to a radial member movable into proximity with said first mentioned radial member when said cover is furled, and means for moving the outer ends of said radial members along said track to cover and uncover said portion of said amphitheater.

11. In a flexible roof furling system for amphitheaters or the like, in combination, an arcuate track adjacent the periphery of the portion of said amphitheater to be covered, a beam arching over said portion, said beam extending at least to the position of the axis about which the arc in said track is described, a plurality of radial members pivotally connected at their inner ends to said beam adjacent said axis, a plurality of wheeled means movable on said track and respectively connected to the outer ends of said radial members, means for spacing adjoining radial members, a flexible cover being secured at one end thereof to a radial member and extending across the other radial members and having its other end secured to a radial member movable into proximity with said first mentioned radial member when said cover is furled, means for anchoring the radial member connected to one of said ends of said cover, and means for moving the radial member connected to the other of said ends of said cover, whereby as said lastmentioned radial member is moved, said radial members are fanned open or closed in spaced relation to adjoining radial members.

12. In a flexible roof furling system for amphitheaters or the like, having a floor in combination, a circular track adjacent the periphery of said amphitheater, a vertical support positioned above the floor in said amphitheater, said vertical support substantially coinciding with the axis of said circular track, radial members extending between said vertical support and said track, means for connecting the respective ends of said radial members to said support and said track, a ring gear parallel to said track and adjacent thereto, ratchet means on said ring gear, and drive means for rotating said ring gear in one direction to cause said ratchet means to engage the radial members respectively to fan them into open position, said drive means being further adapted to rotate said ring gear in the other direction to close said radial members, and a flexible cover for said radial members, said cover being secured at one end thereof to a radial member and extending across the other radial members and having its other end secured to a radial member movable into proximity with said first mentioned radial member when said cover is furled.

13. In a flexible roof furling system for amphitheaters or the like, in combination, a cantilever beam arching inwardly from the rear of said amphitheater to the center of the same so as not to obstruct the view of the spectators within the amphitheater, a circular track around the periphery of the amphitheater, a plurality of radial members on each side of said beam pivotally connected at their inner ends to said beam about said center, the outer ends of said radial members being connected to said track, said radial members on each side of said beam being adapted. to be extended in fanwise fashion over one-half of said amphitheater, a flexible cover being secured at one end thereof to a radial member and extending across the other radial members and having its other end secured to a radial member movable into proximity with said first mentioned radial member when said cover is furled, means for holding in substantially fixed position radial members connected to said ends of said cover adjoining said beam, means for moving radial members respectively connected at the other end of said radial cover along said track on each side of said beam, and means for making a weatherproof joint between said last-mentioned radial members when said radial members are fully opened.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 641,946 McFarland Jan. 23, 1900 2,432,620 Ferguson Dec. 16, 1947 FOREIGN PATENTS Number Country Date 663,576 Germany of 1938 106,466 Australia of 1939 

